Cigarette smoking is the leading preventable cause of morbidity and mortality in the U.S. Our previous studies have demonstrated that exercise used as an adjunct to smoking cessation programs, results in substantially higher abstinence rates. Research by our team and others indicates that exercise may mediate smoking outcomes by reducing cigarette craving, nicotine withdrawal symptoms and by improving mood while quitting smoking. Yoga is an ancient, multi-component system consisting of both mental and physical practices or "Sudras". As a form of exercise, yoga shares many of the same properties as traditional (Western) aerobic exercise that we have used in our previous studies. Yoga may also offer additional benefits that may make it an especially effective complimentary treatment for smokers who are attempting to quit. Our ongoing study (R21-AT003669) examines the acceptability and preliminary efficacy of yoga as an adjunct to smoking cessation among women. Neither that study, nor any of our previous work, has included men. Much of the other research concerning exercise and smoking cessation has also tended to focus on women smokers. Thus, in the growing literature on the efficacy of exercise interventions for smokers, men are inadequately represented and research findings may not generalize to them or address their needs. In this competitive revision we will recruit 40 men who want to quit smoking and provide cognitive- behavioral therapy for smoking cessation once weekly for 10 weeks. Participants will be randomly assigned to receive either;(1) Yoga or (2) a Wellness program (contact-control), twice weekly throughout the program. All participants will be assessed for changes in smoking behavior, psychosocial variables relevant to smoking cessation, exercise adoption, and other psychological constructs that may act as mechanisms of action (mediators) of yoga and smoking cessation. These variables include;affect, perceived stress, mindfulness, self-esteem, quality of life and group cohesion. Focus groups will be used to collect qualitative data at the end of each cohort. This study is designed to provide key data necessary to establish several research fundamentals necessary to support a full scale efficacy trial. These include: 1) establishing intervention feasibility and acceptability among men who smoke, 2) piloting recruitment and retention procedures and identifying barriers to participation, 3) obtaining qualitative feedback from participants to enhance treatment content and/or design, 4) establishing anticipated effect size estimates, and 5) identifying likely mechanisms of action (mediators) that may be responsible for intervention efficacy. This application responds to NOT-OD-09-058: "NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications." PUBLIC HEALTH RELEVANCE: There is an important and growing research literature on how exercise interacts with substance use, especially tobacco cessation. However, men are under-represented in this research. This study will substantially expand our ongoing study to include an exploration of important treatment features, including acceptability, initial efficacy and mechanisms of action of yoga as a complementary treatment for tobacco cessation among men.